Kolomiets O. Transmembrane Ca2+ exchange in myometrial mitochondria in conditions of nitric oxide and calix[4]arene influence

Object: isolated mitochondria and myocytes of rat uterus. Aim: to study transmembrane exchange of Ca ions in mitochondria from rat uterus and polarization of mitochondria membrane under influence of nitrogen oxide and calixarenes. Methods: preparative biology, spectrophotometry, spectrofluorimetry, flow cytometry, photon correlation spectrometry, light, electron and laser confocal microscopy, kinetic and statistic analysis. It is confirmed, that Ca2+-sensitive fluorescent dye Fluo-4 AM can be used for investigation Ca2+ exchange regularities in myometrium mitochondria. It is shown that nitric oxide increase energy-dependent accumulation of Ca ions in myometrial mitochondria. This effect is mediated by Ca2+-uniporter activation and do not dependent on PTP functioning. It is investigated Ca2+/H+-exchange properties in inner membrane of myometrium mitochondria, namely this exchange has stoichiometry 1:1 and functioning in different pH. It is found that Ca2+/H+ exchange resistant to nitric oxide influence, but stimulated by calix[4]arene C-97, C-99 and amiloride and inhibited by Mg ions. It is established that potential-sensitive dye of cyanide group DіOC6(3) binds with energized mithochondia and can be used for testing mitochondrial potential changes. It is confirmed that nitric oxide cause mitochondrial inner membrane potential decrease. It is shown that calix[4]arene C-97 and C-99 provoke transient mitochondrial inner membrane polarization, which cohere with its stimulating influence on Ca2+/H+-exchange.